Screen printing machine and cylindrical screen mounting



1967 J. B. VAN DER WINDEN SCREEN PRINTING MACHINE AND CYLINDRICAL SCREEN MOUNTING 2 Sheets-Sheet 1 Filed Sept. 11, 1964 JNVENTOR. JOHANNES B. VAN DER WINDEN ATTORNEYS.

9 J. B. VAN DER WINDEN 3,304,860

SCREEN PRINTING MACHINE AND CYLINDRICAL SCREEN MOUNTING 2 SheetsSheet 2 Filed Sept. 11, 1964 INVENTOR. JOHANNES B VAN DER WINDEN BY ATTORNEYS.

United States Patent 3,304,860 SCREEN PRINTING MACHINE AND CYLINDRI- CAL SCREEN MOUNTING Johannes Bernardus van der Winden, Amstelveen, Netherlands, assignor to Gebr. Stork & Cos Apparatenfabriek N.V., Amsterdam, Netherlands Filed Sept. 11, 1964, Ser. No. 395,878 Claims priority, application Netherlands, Sept. 12, 1963, 297,819 7 Claims. (Cl. 101-116) My invention relates to a screen printing machine, comprising a movable surface for supporting material to be printed upon and further comprising at least two hearing devices, each for one cylindrical screen which is adapted to cooperate with the supporting surface, and a mechanism for mutually coupling rotatively the various bearing devices.

Several variants of such a machine are known, one of the problems involved consisting in that when the screens are mounted in the bearing devices, care should be taken that the angular position of each screen be adjusted to that of the other screens. In other words, when the screens are mounted it is necessary to watch the so-called registration between the various screens. Hitherto use Was generally made of index points, which must be accurately indexed by sight to a given point in the bearing device.

This method is still possible with a machine operating only with screens of one type, ie with one given screen diameter, but as soon as screens of a different type are to be used, considerable complications and time-consuming adjustments in the machine are encountered.

It is a first object of my invention to provide a considerable simplification in this respect and to make possible a very simple indexing of each of the screens, only a slight adjustment, if any, being required after the screens have been mounted.

My invention further aims at obtaining a considerable simplification in indexing, and also in the mounting and removal of a screen.

The invention will be explained in greater detail by reference to the drawing, which shows a diagrammatic illustration of a screen printing machine.

FIG. 1 is a side view of the machine, in which the essential elements are shown.

FIG. 2 is a section on an enlarged scale, in a plane at right angles to that of FIG. 1, of a bearing device with a cylindrical screen mounted therein.

As can be seen in FIG. 1, the screen printing machine consists of a frame 1, on which is arranged an endless belt 2, which is adapted to travel in a continuous path between a driving pulley 3 and an idler 4. In the operative path 5 this belt 2 forms a surface for supporting the I material 6 to be printed upon, which is unrolled from a supply roll, not shown. Mounted on the frame 1 is a driving motor 7, which transmits the driving force via a connecting rod 8 to the pulley 3. Above the path 5 are provided a number of bearing devices 9 for cylindrical screens 10. The material 6 printed upon is delivered, on the side of the machine to the left of FIG. 1, to an apparatus, not illustrated, for the further treatment of this material. On the underside of the continuous path traversed by the belt 2 a device 11 for washing the belt, a tension device 12, and a device 13 for applying an adhesive layer on the belt 2 are present, so that after passing around the idler 4 this belt can support the material 6 to be printed upon and grip it temporarily. After the material 6 has been released at the end of the machine to the left of FIG. 1, the remnants of adhesive are removed from the belt 2 by means of the washing device 11.

Each of the screens 10 is provided at its ends with an adapter ring 14, which serves in the first place to secure the screen in the bearing device 9, and also to adapt the diameter of the screen to the diameter of the supporting element of the bearing device 9 on which the end of the screen is directly supported. As can be seen in FIG. 2, this supporting element is formed by a sleeve 15, whose outer circumference is provided with teeth 16 forming part of its drive coupling with another bearing device. This coupling comprises the gear wheels 17 and 18 as well as the worm drive 19. The latter is described in greater detail in, and forms the subject-matter of, my copending patent application Serial No. 395,656, filed September 11, 1964.

Fitted on the supporting sleeve 15 is a locking member 20, in the form of a key, which cooperates with a complementary locking member in the ring 14 of the screen, in this case a groove. Inside the supporting sleeve 15 a tube 21 is rotatably supported, this tube being provided at its inner end with screw thread 22, adapted to cooperate with a mating screw thread on the ring 14 of the screen. The part of the tube 21 protruding beyond the sleeve 15 is provided with a collar 23, which abuts the outer end of the sleeve 15. This collar can be engaged by a spanner (not shown) for tightening the tube 21 on the ring 14 of the screen.

At its end directed towards the screen 10 the supporting sleeve 15 is provided with a lengthened portion 24 which extends over an arc of nearly 180, in the centre of which portion the locking key 20 is fitted. This lengthened portion forms a saddle, in which the ring 14 of the screen 10 is seated.

Each screen ring 14 is provided with at least one key groove for cooperation with the key 20. The number and the arrangement of these grooves depends on the diameter of the screen 10 and the centre distance between two adjacent bearing devices 9. A value that can be used in practice consists of a centre distance of 320 mm. between two bearing devices for use with screens having a circumference of 480 or 640 mm. respectively.

If a screen having a circumference of 480 mm. is used,

, this means that, starting from a given screen, each succeeding screen must be rotated through an angle of 240 in order to obtain correct registration. For screens of this type, three groove-s staggered over will be provided in the adapter ring 14. If these three grooves are marked with different index points, the same index point can be applied cyclically from the first bearing device to the last, so that the operator, when mounting a screen in any given bearing device, can at once and without any ditficu lty set the correct registration of the screen in question with the other screens.

If a screen having a circumference of 640 mm. is used, two key grooves are provided diametrically opposite each other on each adapter ring 14, these grooves alternately cooperating, in the series of adjacent screens, with the keys 20 of the corresponding supporting sleeves 15.

In a screen printing machine there is on the one hand the aim to mount as many cylinders as possible within the minimum length of the machine and on the other hand to maintain a sufiicient view of the material to be printed for inspection purposes. This can be achieved The improvement which forms the principal subjectmatter of my invention and which consists in the provision of a locking member in the supporting element of the bearing device for each screen, which member is adapted to cooperate with a complementary locking memher in the end of the screen, causes a very great gain of time and simplification when a series of screens is to be mounted in a screen printing machine. The advantage is even more pronounced when the machine is to be adapted for the use of screens having different diameters.

What I claim is:

l. A screen printing machine comprising a movable surface for supporting material to be printed upon, a cylindrical screen disposed adjacent said surface for printing on material supported by said surface, said screen having an adaptor ring on each end thereof, a bearing device for supporting said screen, said bearing device having means for supporting each screen adaptor ring and including a driven sleeve having a segmental arcuate projection having an are not greater than 180 and extending from one end thereof toward the screen and constituting a saddle seating said screen adaptor ring beyond said one end of said sleeve for ready mounting and removal of said ring relative to said saddle, means in said sleeve releasably retaining said ring in said saddle, and lock means between said saddle and said ring for rotatively securing said sleeve and screen.

2. A screen printing machine according to claim 1 wherein said lock means comprises a key disposed centrally of said saddle projection, and a plurality of keyways in each adaptor ring and symmetrically spaced therearound for selective engagement with said key for indexing the respective screen.

3. A screen printing machine comprising a movable surface for supporting material to be printed upon, a plurality of cylindrical screens disposed adjacent said surface for printing on material supported by said surface, said screens having an adaptor ring on each end thereof, a plurality of bearing devices for respectively supporting said screens and including means for supporting said screen adaptor rings, means coupling said bearing device supporting means for simultaneous rotation of said screens, each said supporting means including a sleeve having means engaging said coupling means and a tube rotatable within said sleeve, said screen adaptor ring being mounted in the inner end of said sleeve and threadedly engaged with the inner end of said tube, lock means between said sleeve and said ring and including a key in said sleeve and a keyway on said ring, and a collar on the outer end of said tube and abutting the outer end of said sleeve for rotating said tube to adjust said screen ring axially of said sleeve.

4. A screen printing machine according to claim 3, wherein each supporting sleeve has a semicylindrical projection on its inner end and constituting a saddle supporting the respective adaptor ring, the locking key being disposed centrally of the arc of said saddle projection.

5. A screen printing machine according to claim 3 wherein the circumference of each screen has a value which equals 1 /2 to 2 times the center distance between two adjacent bearing devices.

6. A screen printing machine according to claim 3 wherein the center distance between two adjacent bearing devices is 320 mm.

7. A screen printing machine according to claim 3 wherein said adaptor rings are provided with a plurality of keyways spaced symmetrically therearound for selective cooperation with said key for indexing the respective screen.

References Cited by the Examiner UNITED STATES PATENTS 637,565 11/1899 Hett 101-119 X 2,071,824 2/1937 Engert 101--116 2,468,400 4/1949 Huebner 101119 2,928,340 3/1960 Stein et a1. 101120 FOREIGN PATENTS 844,557 8/ 1960 Great Britain.

ROBERT E. PULFREY, Primary Examiner.

H. P. EWELL, Assistant Examiner. 

1. A SCREEN PRINTING MACHINE COMPRISING A MOVABLE SURFACE FOR SUPPORTING MATERIAL TO BE PRINTED UPON, A CYLINDRICAL SCREEN DISPOSED ADJACENT SAID SURFACE FROM PRINTING ON MATERIAL SUPPORTED BY SAID SURFACE, SAID SCREEN HAVING AN ADAPTOR RING ON EACH END THEREOF, A BEARING DEVICE FOR SUPPORTING EACH SCREEN ADAPTOR RING. HAVING MEANS FOR SUPPORTING EACH SCREEN ADAPTOR RING AND INCLUDING A DRIVEN SLEEVE HAVING A SEGMENTAL ARCUATE PROJECTION HAVING AN ARC NOT GREATER THAN 180* AND EXTENDING FROM ONE END THEREOF TOWAZRD THE SCREEN AND CONSTITUTING A SADDLE SEATING SAID SCREEN ADAPTOR RING BEYOND SAID ONE END OF SAID SLEEVE FOR READY MOUNTING AND REMOVAL OF SAID RING RELATIVE TO SAID SADDLE, MEANS IN SAID SLEEVE RELEASABLY RETAINING SAID RING IN SAID SADDLE, AND LOCK MEANS BETWEEN SAID SADDLE AND SAID RING FOR ROTATIVELY SECURING SAID SLEEVE AND SCREEN. 